This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The objective of this project is to develop an animal model of human strabismus. To provide an animal model of human exotropia, a free tenotomy was preformed in infant macaques of the medial recti. When the animals were old enough to record eye movements with video eye trackers, we measured their ductions, ocular alignment, comitance, smooth pursuit, fixation preference, and gaze stability.